feat: show live output from the Helm binary (#286)

* feat: show live output from the Helm binary

Signed-off-by: Rodrigo Fior Kuntzer <rodrigo@miro.com>

* fixup! Merge branch 'main' into enable-live-output

Signed-off-by: Yusuke Kuoka <ykuoka@gmail.com>

pkg/helmexec/runner_test.go

@@ -0,0 +1,88 @@
+package helmexec
+
+import (
+	"bytes"
+	"os/exec"
+	"reflect"
+	"strings"
+	"testing"
+)
+
+func TestShellRunner_Execute(t *testing.T) {
+	tests := []struct {
+		name             string
+		want             []byte
+		stdoutWant       string
+		enableLiveOutput bool
+	}{
+		{
+			name:             "echo_template_no_live_output",
+			want:             []byte("template\n"),
+			enableLiveOutput: false,
+		},
+		{
+			name:             "echo_template_enable_live_output",
+			want:             nil,
+			enableLiveOutput: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var buffer bytes.Buffer
+			shell := ShellRunner{
+				Logger: NewLogger(&buffer, "debug"),
+			}
+			got, err := shell.Execute("echo", strings.Split("template", " "), map[string]string{}, tt.enableLiveOutput)
+
+			if err != nil {
+				t.Errorf("Execute() has produced an error = %v", err)
+				return
+			}
+			if !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("ExecuteStdIn() got = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestLiveOutput(t *testing.T) {
+	tests := []struct {
+		name    string
+		cmd     *exec.Cmd
+		wantW   string
+		wantErr bool
+	}{
+		{
+			name:    "echo_template",
+			cmd:     exec.Command("echo", "template"),
+			wantW:   "template\n",
+			wantErr: false,
+		},
+		{
+			name: "helm_template",
+			cmd:  exec.Command("helm", "template"),
+			wantW: `Error: "helm template" requires at least 1 argument
+
+Usage:  helm template [NAME] [CHART] [flags]
+`,
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			w := &bytes.Buffer{}
+			got, err := LiveOutput(tt.cmd, w)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("LiveOutput() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if gotW := w.String(); gotW != tt.wantW {
+				t.Errorf("LiveOutput() gotW = %v, want %v", gotW, tt.wantW)
+			}
+			if got != nil {
+				t.Errorf("LiveOutput() got unespected %v", got)
+			}
+		})
+	}
+}